Radiochemical Studies of the Fission of U235 Induced by Helium Ions

The absolute fission yields of approximately twenty-five nuclides from the helium-ion-induced fission of ${\mathrm{U}}^{235}$ were determined with an accuracy of \ifmmode\pm\else\textpm\fi{}5-15% for several energies ranging from 20 to 40 Mev. Such features of fission as the symmetric-asymmetric modes of fission, the relation of total fission cross section to compound nucleus theory, fine structure in fission product distribution, valley to peak ratios, and neutron emission are discussed as well as some of the experimental detail involved.